Recently, I purchased a William Joseph Boat Thermometer from the Caddis Fly and affixed it to my gunwhale and got to taking some water temps. The unit is housed in an orange shock guard and attached to any rail via bungee type cords on the rear of the device. A cord with a sensing unit dangles off the device and into the water taking continuous measurements. The thermometer is solar powered and has a 12 hour battery back-up for overcast days. The display is digital, large and fairly easy to read. I have had to cup my hand over it I in order to read the display in the direct sun.
I have recorded temperatures between 43 (early morning on the Mckenzie) and 117 degrees (in a cup of coffee) so it appears to have range required for fishing our waterways and then some. I really like the fact that it is in the water continuously and since I have had it I have noticed patterns in the hatches. Leaving the thermometer in the water all day, you can look at it at your convenience. I’ve had other thermometers that you have to take discreet measurements with and what I’ve found is that they stay in my pack–I’m out there to fish not to take water quality samplings and I have a hard time stopping fishing to take measurements! With this thermometer I don’t have to stop fishing to gain the benefits of knowing the water temp.
The bottom line is that this is a quality device and if you do a fair amount of fishing from a boat is well worth the forty dollar price tag.–KM